[IPSEC]: Sync series - acquire insert

This introduces a feature similar to the one described in RFC 2367:
"
   ... the application needing an SA sends a PF_KEY
   SADB_ACQUIRE message down to the Key Engine, which then either
   returns an error or sends a similar SADB_ACQUIRE message up to one or
   more key management applications capable of creating such SAs.
   ...
   ...
   The third is where an application-layer consumer of security
   associations (e.g.  an OSPFv2 or RIPv2 daemon) needs a security
   association.

        Send an SADB_ACQUIRE message from a user process to the kernel.

        <base, address(SD), (address(P),) (identity(SD),) (sensitivity,)
          proposal>

        The kernel returns an SADB_ACQUIRE message to registered
          sockets.

        <base, address(SD), (address(P),) (identity(SD),) (sensitivity,)
          proposal>

        The user-level consumer waits for an SADB_UPDATE or SADB_ADD
        message for its particular type, and then can use that
        association by using SADB_GET messages.

 "
An app such as OSPF could then use ipsec KM to get keys

Signed-off-by: Jamal Hadi Salim <hadi@cyberus.ca>
Signed-off-by: David S. Miller <davem@davemloft.net>

Author: Jamal Hadi Salim

include/net/xfrm.h

@@ -214,10 +214,10 @@ extern int xfrm_policy_register_afinfo(struct xfrm_policy_afinfo *afinfo);
 extern int xfrm_policy_unregister_afinfo(struct xfrm_policy_afinfo *afinfo);
 extern void km_policy_notify(struct xfrm_policy *xp, int dir, struct km_event *c);
 extern void km_state_notify(struct xfrm_state *x, struct km_event *c);
-
 #define XFRM_ACQ_EXPIRES	30
 
 struct xfrm_tmpl;
+extern int km_query(struct xfrm_state *x, struct xfrm_tmpl *t, struct xfrm_policy *pol);
 struct xfrm_state_afinfo {
 	unsigned short		family;
 	rwlock_t		lock;

net/xfrm/xfrm_state.c

@@ -57,7 +57,7 @@ static int __xfrm_state_delete(struct xfrm_state *x);
 static struct xfrm_state_afinfo *xfrm_state_get_afinfo(unsigned short family);
 static void xfrm_state_put_afinfo(struct xfrm_state_afinfo *afinfo);
 
-static int km_query(struct xfrm_state *x, struct xfrm_tmpl *t, struct xfrm_policy *pol);
+int km_query(struct xfrm_state *x, struct xfrm_tmpl *t, struct xfrm_policy *pol);
 static void km_state_expired(struct xfrm_state *x, int hard);
 
 static void xfrm_state_gc_destroy(struct xfrm_state *x)
@@ -925,7 +925,7 @@ void km_state_expired(struct xfrm_state *x, int hard)
  * We send to all registered managers regardless of failure
  * We are happy with one success
 */
-static int km_query(struct xfrm_state *x, struct xfrm_tmpl *t, struct xfrm_policy *pol)
+int km_query(struct xfrm_state *x, struct xfrm_tmpl *t, struct xfrm_policy *pol)
 {
 	int err = -EINVAL, acqret;
 	struct xfrm_mgr *km;
@@ -939,6 +939,7 @@ static int km_query(struct xfrm_state *x, struct xfrm_tmpl *t, struct xfrm_polic
 	read_unlock(&xfrm_km_lock);
 	return err;
 }
+EXPORT_SYMBOL(km_query);
 
 int km_new_mapping(struct xfrm_state *x, xfrm_address_t *ipaddr, u16 sport)
 {

net/xfrm/xfrm_user.c

@@ -1232,6 +1232,58 @@ static int xfrm_flush_policy(struct sk_buff *skb, struct nlmsghdr *nlh, void **x
 	return 0;
 }
 
+static int xfrm_add_acquire(struct sk_buff *skb, struct nlmsghdr *nlh, void **xfrma)
+{
+	struct xfrm_policy *xp;
+	struct xfrm_user_tmpl *ut;
+	int i;
+	struct rtattr *rt = xfrma[XFRMA_TMPL-1];
+
+	struct xfrm_user_acquire *ua = NLMSG_DATA(nlh);
+	struct xfrm_state *x = xfrm_state_alloc();
+	int err = -ENOMEM;
+
+	if (!x)
+		return err;
+
+	err = verify_newpolicy_info(&ua->policy);
+	if (err) {
+		printk("BAD policy passed\n");
+		kfree(x);
+		return err;
+	}
+
+	/*   build an XP */
+	xp = xfrm_policy_construct(&ua->policy, (struct rtattr **) xfrma, &err);        if (!xp) {
+		kfree(x);
+		return err;
+	}
+
+	memcpy(&x->id, &ua->id, sizeof(ua->id));
+	memcpy(&x->props.saddr, &ua->saddr, sizeof(ua->saddr));
+	memcpy(&x->sel, &ua->sel, sizeof(ua->sel));
+
+	ut = RTA_DATA(rt);
+	/* extract the templates and for each call km_key */
+	for (i = 0; i < xp->xfrm_nr; i++, ut++) {
+		struct xfrm_tmpl *t = &xp->xfrm_vec[i];
+		memcpy(&x->id, &t->id, sizeof(x->id));
+		x->props.mode = t->mode;
+		x->props.reqid = t->reqid;
+		x->props.family = ut->family;
+		t->aalgos = ua->aalgos;
+		t->ealgos = ua->ealgos;
+		t->calgos = ua->calgos;
+		err = km_query(x, t, xp);
+
+	}
+
+	kfree(x);
+	kfree(xp);
+
+	return 0;
+}
+
 
 #define XMSGSIZE(type) NLMSG_LENGTH(sizeof(struct type))
 
@@ -1243,6 +1295,7 @@ static const int xfrm_msg_min[XFRM_NR_MSGTYPES] = {
 	[XFRM_MSG_DELPOLICY   - XFRM_MSG_BASE] = XMSGSIZE(xfrm_userpolicy_id),
 	[XFRM_MSG_GETPOLICY   - XFRM_MSG_BASE] = XMSGSIZE(xfrm_userpolicy_id),
 	[XFRM_MSG_ALLOCSPI    - XFRM_MSG_BASE] = XMSGSIZE(xfrm_userspi_info),
+	[XFRM_MSG_ACQUIRE     - XFRM_MSG_BASE] = XMSGSIZE(xfrm_user_acquire),
 	[XFRM_MSG_UPDPOLICY   - XFRM_MSG_BASE] = XMSGSIZE(xfrm_userpolicy_info),
 	[XFRM_MSG_UPDSA       - XFRM_MSG_BASE] = XMSGSIZE(xfrm_usersa_info),
 	[XFRM_MSG_FLUSHSA     - XFRM_MSG_BASE] = XMSGSIZE(xfrm_usersa_flush),
@@ -1266,6 +1319,7 @@ static struct xfrm_link {
 	[XFRM_MSG_GETPOLICY   - XFRM_MSG_BASE] = { .doit = xfrm_get_policy,
 						   .dump = xfrm_dump_policy   },
 	[XFRM_MSG_ALLOCSPI    - XFRM_MSG_BASE] = { .doit = xfrm_alloc_userspi },
+	[XFRM_MSG_ACQUIRE     - XFRM_MSG_BASE] = { .doit = xfrm_add_acquire   },
 	[XFRM_MSG_UPDPOLICY   - XFRM_MSG_BASE] = { .doit = xfrm_add_policy    },
 	[XFRM_MSG_UPDSA       - XFRM_MSG_BASE] = { .doit = xfrm_add_sa        },
 	[XFRM_MSG_FLUSHSA     - XFRM_MSG_BASE] = { .doit = xfrm_flush_sa      },